Nickel-Based Alloy

ABSTRACT

Nickel-based alloy, consisting of (in % by mass) Al 1.2-&lt;2.0% Si 1.2-&lt;1.8% C 0.001-0.1% S 0.001-0.1% Cr 0.03-0.1% Mn 0.03-0.1% Cu max. 0.1% Fe 0.02-0.2% Mg 0.005-0.06% Pb max. 0.005% Y 0.05-0.15% and Hf 0.05-0.10% or Y 0.05-0.15% and La 0.05-0.10% or Y 0.05-0.15% and Hf 0.05-0.10% and La 0.05-0.10% Ni remainder together with manufacturing-related impurities.

BACKGROUND OF THE INVENTION

The invention relates to a nickel-based alloy having silicon, aluminum,and reactive elements as alloy components.

Nickel-based alloys are used inter alia for producing electrodes forignition elements in internal combustion engines. Two damagingmechanisms affect the wear of such electrodes, specifically hightemperature corrosion and spark erosion.

Wear from high temperature corrosion can be determined by measuringlosses in weight and using metallographic examinations after exposure topre-specified testing temperatures.

Spark erosion is combustion of material that is caused by ignitionsparks. With each flashover, a limited volume of electrode material ismelted and in part evaporated.

The type of oxide layer formation is particularly significant for bothdamaging mechanisms.

Different alloy elements for nickel-based alloys are known for attainingoptimum oxide layer formation for the specific application. Thus, forinstance, aluminum has a positive effect on oxide layer formation. It isalso known that reactive elements can improve the adhesion of the oxidelayer that forms and can increase life cycle.

Known from GB-A 2031950 is a nickel alloy comprising (in % by weight)about 0.2 to 3% Si, about 0.5% or less Mn, at least two metals selectedfrom the group comprising about 0.2 to 3% Cr, about 0.2 to 3% Al, andabout 0.01 to 1% Y, and the remainder nickel.

DE-A 102 24 891 suggests an alloy that is based on nickel and that has(in % by weight) 1.8 to 2.2% silicon, 0.05 to 0.1% yttrium and/orhafnium and/or zirconium, 2 to 2.4% aluminum, and the remainder nickel.It is very difficult to process such alloys given the high aluminum andsilicon content and they are thus not well suited for use on anindustrial scale.

SUMMARY OF THE INVENTION

The object of the inventive subject-matter is to provide a nickel-basedalloy that can be used to increase the life cycle of components producedtherefrom by increasing resistance to spark erosion and oxidation whilesimultaneously providing good formability and weldability.

This object is attained using a nickel-based alloy that contains (in %by weight):

-   -   Al 1.2-<2.0%    -   Si 1.2-<1.8    -   C 0.001-0.1%    -   S 0.001-0.1%    -   Cr 0.03-0.1%    -   Mn 0.03-0.1%    -   Cu max. 0.1%    -   Fe 0.02-0.2%    -   Mg 0.005-0.06%    -   Pb max. 0.005%    -   Y 0.05-0.15% and Hf 0.05-0.10% or    -   Y 0.05-0.15% and La 0.05-0.10% or    -   Y 0.05-0.15% and Hf 0.05-0.10% and La 0.05-0.10%    -   Ni remainder and production-related impurities

Preferred alternative embodiments of the inventive subject-matter are asfollows.

Nickel-based alloy having (in % by weight):

-   -   Al 1.2-<2.0%    -   Si 1.2-<1.8    -   C 0.001-0.05%    -   S 0.001-0.05%    -   Cr 0.03-0.1%    -   Mn 0.03-0.1%    -   Cu max. 0.1%    -   Fe 0.02-0.2%    -   Mg 0.005-0.06%    -   Pb max. 0.005%    -   Y 0.10-0.15% and Hf 0.05-0.10%    -   Ni remainder and production-related impurities

Nickel-based alloy having (in % by weight):

-   -   Al 1.2-<2.0%    -   Si 1.2-<1.8    -   C 0.001-0.05%    -   S 0.001-0.05%    -   Cr 0.03-0.1%    -   Mn 0.03-0.1%    -   Cu max. 0.1%    -   Fe 0.02-0.2%    -   Mg 0.005-0.06%    -   Pb max. 0.005%    -   Y 0.10-0.15% and La 0.05 to 0.10%    -   Ni remainder and production-related impurities

Nickel-based alloy having (in % by weight):

-   -   Al 1.2-<2.0%    -   Si 1.2-<1.8    -   C 0.001-0.05%    -   S 0.001-0.05%    -   Cr 0.03-0.1%    -   Mn 0.03-0.1%    -   Cu max. 0.1%    -   Fe 0.02-0.2%    -   Mg 0.005-0.06%    -   Pb max. 0.005%    -   Y 0.10-0.15% and Hf 0.05-0.10% and La 0.05-0.10%

Thus, there are three conceivable variants in terms of the reactiveelements, specifically:

-   -   Y+Hf    -   Y+La and    -   Y+Hf+La

The inventive nickel-based alloy can preferably be used as a materialfor electrodes for spark plugs in gasoline engines.

Selectively adjusting the elements Al, Si, Cr, Mn, and Mg, as well asthe reactive elements Y, Hf, La in their respective combinations canbring about an increased life cycle for electrode materials byincreasing the spark erosion resistance and oxidation resistance whilesimultaneously promoting formability and weldability.

The element Mg is particularly important in terms of binding sulfur sothat in this case it is possible to selectively adjust low sulfurcontent in the inventive nickel-based alloy.

Preferred aluminum content (in % by weight) ranges from 1.2-1.5%.

Preferred silicon content (in % by weight) ranges from between 1.2 and1.8%, in particular 1.2 and 1.5%, while the preferred Mg content (in %by weight) is adjusted between 0.008 and 0.05%.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are plots of the results of laboratory tests.

DETAILED DESCRIPTION OF THE INVENTION

The table compares five inventive laboratory batches to two industrialbatches belonging to the prior art.

Laboratory batch 1132 is an example in which the reactive elements Y+Hfare provided in the inventive nickel-based alloy.

Laboratory batch 1140 is an example in which the reactive elements Y+Laare present in the inventive alloy.

Laboratory batches 1141 and 1142 disclose examples in which Y+La+Hf wereadjusted as reactive elements in the inventive nickel-based alloy.

Ele- LB LB LB LB ment 1132 1140 1141 1142 NiCr2MnSi NiAl1Si1Y Ni 96.8396.91 96.89 96.79 96.24 97.56 Si 1.47 1.36 1.36 1.42 0.49 0.96 Al 1.381.43 1.44 1.40 0.02 0.98 Zr Y 0.15 0.12 0.14 0.13 0.17 Hf 0.08 0.0780.073 La 0.09 0.096 0.096 Ti 0.1 0.01 0.01 C 0.002 0.006 0.004 0.0030.003 0.03 S 0.002 0.002 0.002 0.002 0.002 0.002 Co 0.04 0.05 Cu 0.010.01 Cr 0.04 0.03 0.06 0.04 1.57 0.01 Zr 0.01 Mg 0.02 0.03 0.01 0.030.02 0.04 Mn 0.06 0.03 0.03 0.06 1.48 0.02 Fe 0.03 0.03 0.03 0.04 0.080.13 Pb 0.001 0.001

FIGS. 1 and 2 depict weight loss examinations for the alloys inaccordance with the table at temperatures of 900° C. and 1000° C.

At just 900° C. the two comparison alloys exhibit flaking of thepreviously constructed oxide layer. Although this also occurs with theinventive alloys at 1000° C., it does not occur to the same extent as inthe comparison alloys.

1. Nickel-based alloy comprising, in % by weight: Al 1.2-<2.0% Si1.2-<1.8 C 0.001-0.1% S 0.001-0.1% Cr 0.03-0.1% Mn 0.03-0.1% Cu max.0.1% Fe 0.02-0.2% Mg 0.005-0.06% Pb max. 0.005% Y 0.05-0.15% and Hf0.05-0.10% or Y 0.05-0.15% and La 0.05-0.10% or Y 0.05-0.15% and Hf0.05-0.10% and La 0.05-0.10% Ni remainder and production-relatedimpurities
 2. Nickel-based alloy in accordance with claim 1, comprising,in % by weight: Al 1.2-<2.0% Si 1.2-<1.8 C 0.001-0.05% S 0.001-0.05% Cr0.03-0.1% Mn 0.03-0.1% Cu max. 0.1% Fe 0.02-0.2% Mg 0.005-0.06% Pb max.0.005% Y 0.10-0.15% and Hf 0.05-0.10% Ni remainder andproduction-related impurities
 3. Nickel-based alloy in accordance withclaim 1, comprising, in % by weight: Al 1.2-<2.0% Si 1.2-<1.8 C0.001-0.05% S 0.001-0.05% Cr 0.03-0.1% Mn 0.03-0.1% Cu max. 0.1% Fe0.02-0.2% Mg 0.005-0.06% Pb max. 0.005% Y 0.10-0.15% and La 0.05to 0.10%Ni remainder and production-related impurities
 4. Nickel-based alloy inaccordance with claim 1, further comprising, in % by weight: Al1.2-<2.0% Si 1.2-<1.8 C 0.001-0.05% S 0.001-0.05% Cr 0.03-0.1% Mn0.03-0.1% Cu max. 0.1% Fe 0.02-0.2% Mg 0.005-0.06% Pb max. 0.005% Y0.10-0.15% and Hf 0.05-0.10% and La 0.05-0.10% Ni remainder andproduction-related impurities
 5. Nickel-based alloy in accordance withany of claims 1 through 4, further comprising, in % by weight: Al1.2-1.5% Si 1.2-1.5%
 6. Nickel-based alloy in accordance with any ofclaims 1 through 4, further comprising, in % by weight: Mg 0.008-0.05%7. Nickel-based alloy in accordance with any of claims 1 through 4,further comprising, in % by weight: Y+Hf 0.11-0.18%
 8. Nickel-basedalloy in accordance with any of claims 1 through 4, further comprising,in % by weight: Y+La 0.11-0.18%
 9. Nickel-based alloy in accordance withany of claims 1 through 4, further comprising, in % by weight: Y+Hf+La0.18-0.22%
 10. Nickel-based alloy in accordance with any of claims 1through, further comprising, in % by weight: Y+Mg 0.11-0.13%
 11. A sparkplug electrode comprising the nickel-based alloy in accordance with anyof claims 1 through 4.